I'll just mention that I did study Japanese in Vancouver under 100/101 classes, so I'm familiar with speaking and reading to an extent, but not fluent. (Writing's going to be a different thing).
Since I want to do my part of translation (that and the person who I collaborated with for a few months hasn't returned my e-mails, so I think he's AWOL) and work on my Japanese, I just wonder if I need to read up on more vocabulary before I start doing this? For simple words, I'm okay. But there were times when I needed to pull out the trusty dictionary app from my Iphone. Which is why I find things more easier if furigana is available from shonen stuff.
Read up? You need to memorize. Vocab, grammar, and kanji. At least to JLPT n3 level.
Nah. I have a group, but the translator I met online hasn't returned my e-mail and I do need to improve my Japanese.
cmertb has a point on looking up kanji found at N4 and 3 levels, but I'm sure my dictionary has them and I probably need to read up on them.
As long as you know your grammar, I don't see why it's wrong to look up kanji or words. Knowing everything from the top of your head will just make it easier and the process of translating will be faster, but it's not necessary. Some people seem to think that being a real translator is all about being able to translate everything without a dictionary. But actually, real, professional translators also use their dictionaries. If I'm to believe my teacher (in translation studies) she often uses 4 or 5 different dictionaries, plus a thesaurus even when she translates fairly easy work...
I've been studying over 5 years (I had Japanese as my major in university for 4 years) and I'm still using my dictionary quite a lot. I often need to look up readings of kanji (or just look up the kanji's meaning and don't even bother with the reading, but...), because there's just an incredible lot of them. I don't think it's wrong at all. More than knowing the readings and meanings of all kanji, I think it's much more important to know the grammar. Without any knowledge of the Japanese grammar rules, you won't be able to effectively translate a sentence, even if you can read all the kanji.
Also, I think translating can actually be a fairy fund way to improve your Japanese. Of course, as long as you doubt your own skills, it's a good idea to have someone check your translations. But aside from that, just give it a try. I think you'll notice soon enough whether or not you know enough Japanese to actually translate something at this moment.
I've yet to meet anyone who thinks you need to translate without a dictionary. I know two languages at near native level and I still use a dictionary when translating between them. However, the idea that you can translate a text of any significant size while having to look up almost every word in a dictionary is so unreasonable for a normal human being that I'm going to have to say it's impossible. You can translate a page or two... then you will quit in frustration. That's why it's important to have some vocab memorized. n3 level seems like the required minimum to me. Same goes for grammar, except it is even more important than vocab. You simply have to have basic grammar patterns internalized, since deciphering a sentence whose grammar you don't understand is far more complicated than looking up a word you don't know. As for kanji, just looking at it logically, it doesn't seem that there is a need to have them memorize if you restrict yourself to only manga with furigana. However, even shounen/shoujo manga have many blocks of text without furigana. You can skip them when you just read, but when you translate, you have to get everything. More practically, I haven't seen any fan translators who say they require furigana to be able to translate, and then can produce an acceptable translation in terms of accuracy even when furigana is available. This is most likely a correlation, but that's the observation I have. So learn those kanji.
On the idea of translation checks, I would vehemently argue against them, also based on my experience. Contrary to expectations, regular TLC probably hinders you from learning the language rather than helps you. The way you learn is by looking up every single thing you're not sure of, and if you are unable to find answers in dictionaries, grammar references, or the internet, you must go and ask questions (and this forum is great for that). As a translator, you should never guess, because you will most likely guess wrong and you won't learn anything either. But if you know that somebody will be checking your work after you then, despite your best intentions, you will end up guessing all the time and let the TLCer sort it out. Not to mention, there are very few fan translators who are sufficiently qualified to TLC (i.e. able to explain to you why they changed your tl). For those whose Japanese isn't perfect, TLC is an extremely frustrating experience, with most grumbling that it would be easier to redo everything from scratch yourself. It's a rare TLCer who can last long.